## Posts Tagged ‘blackjack percentages’

### Blackjack strategy: Not a 12! Noooooo!

Monday, September 27th, 2010

There’s a reason I titled today’s blog Not a 12! Noooooo! First of all, I think it’s a catchy title that should get your attention. If you’re reading this, then it worked (Also, feel free to comment so I know you’re reading). Secondly, a lot of blackjack players freak out when they are dealt a 12 and make the wrong decision. Blackjack basic strategy says to stand against a dealer 4, 5 or 6 and hit against anything else, but a lot of players don’t want to do that.

It’s understandable why. Players are trained to take into account the high ratio of cards with a value of 10. Well, 12 plus 10 equals 22, which busts you. Players then see that they have a 12, imagine a good probability of losing if they hit and decide to stand. The truth is, if you hit a hand of 12, you will probably lose. However, if you stand you will also probably lose, and the odds are a little bit worse. A hard 12 is a bad hand and no matter what you do, the odds are against you, but basic strategy takes all of that into account.

When you have a hand of 12, your decision is based on your odds of busting versus the dealer’s odds of busting. If you hit a hard 12, there are 4 out of 13 cards that can bust you, meaning you have a 31% chance of busting on that hit. That means a 69% chance of surviving hitting the hand. That’s not so scary, is it?

When the dealer has a 4, 5 or 6, his odds of busting are 39.4%, 41.6% and 42.3%, respectively. Those percentages are taking into account the dealer’s odds for having each specific card in the hole and, after assuming the odds for each hand, the odds each hand have of busting. Those are all higher than your chance of busting, so you want to stand against those hands.

The most common mistake that the player makes is standing with a 12 against a dealer 2. The thinking is that the dealer has a 12 and therefore has a good chance of busting. However, he only has a 31% chance of busting with a 12 and likewise, only a 31% of having a 12 in the first place. He could have a hand anywhere from 4 to a soft 13. Taking all of that into account, when the dealer has a 2 as the up card, he has a 35% chance of busting. With those odds, that means you have a 65% chance of losing if you stand on a hard 12, since the dealer will hit up until a 17 or better. Compare that with your 31% chance of busting and it is better to take a hit and hope you improve your hand.

Have all of those statistics confused you? If so, it’s okay. People a lot smarter than me (and probably you) when it comes to math and statistics have tested blackjack basic strategy and determined the odds for everything. If you stick to basic strategy, you should be okay.

### Dealer Up Card Odds

Thursday, April 8th, 2010

To be a good blackjack player, you need to know and understand blackjack basic strategy. Beyond memorizing a simple chart, it is a good idea to know why certain decisions are made. In the past I have posted series of blogs that delve deep into the reasoning behind basic strategy decisions. One of many things that basic strategy takes into account is the probability of busting when drawing a card. This morning, I posted a blog discussing the probability of busting when you (or the dealer) have a certain hand total.

However, one of the difficult things about blackjack is that you don’t know what hand the dealer has. Since the dealer has a hole card face down, you can only guess what his hand is. Luckily, mathematicians a whole lot smarter than me have already calculated the likelihood of the dealer busting based on what his up card is. These statistics are found by determining, based on what up card the dealer has, what hands he is likely to have, and from there determining how likely he is to bust with that hand. A full chart follows.

When looking at these numbers, you may be surprised because the highest hands have the lost bust percentage. That is because the dealer in those cases is likely to have a hand high enough that he would stand rather than drawing again. For example, if the dealer shows a ten-value card, he is not likely to bust because he would stand on a hand of 17-21. If he shows a 10, that means 8 cards (7, 8, 9, 10, J, Q, K, ace) would give the dealer a hand in the 17-21 range and only 5 cards (2, 3, 4, 5, 6) would give him a stiff hand that is likely (31-62%) to bust when he hits.

The following list has 3 numbers. The first is the dealer’s up card. The second number is the dealer’s bust percentage, or the likelihood that the dealer will bust when he has that up card. The third number is the player’s odds when the dealer has that up card. It should be noted that those odds take into account that the player plays perfect strategy. Also, because this doesn’t take into account what hand the player has, the odds will change based on the player’s cards. A percentage in parenthesis means the odds favor the dealer.

Up Card – Dealer Bust % — Player Odds %
2 – 35.3% — 9.8%
3 – 37.56% — 13.4%
4 – 40.28% — 18%
5 – 42.89% – 23.2%
6 – 42.08% – 23.9%
7 – 25.99% — 14.3%
8 – 23.86% — 5.4%
9 – 23.34% — (4.3%)
10 – 21.43% — (16.9%)
Ace – 11.65% — (16%)

### Blackjack Odds: Chance of Busting

Thursday, April 8th, 2010

If you are new to the game of blackjack, whether you prefer to play at online casinos or the brick and mortar variety, you have likely studied the basic strategy charts. You may have even studied the reasons behind each of the player decisions, as I have covered in various series in this blog.

Player decisions are based on the likelihood of your hand beating the dealer’s hand. One thing that plays heavily into that strategy is the odds of busting, both for the dealer and for the player. Anytime you have a certain hand, there are a number of cards that can help you and a number that will not. Depending on the hand, some cards may cause you to bust. Therefore, being a good blackjack players means knowing how likely you and the dealer are to bust. Here is a short guide to help you with that.

Players and dealers can only bust if they have a hand of a hard 12 or more. If you have a 12, there is a 31% chance of busting if you take a hit. Hitting a hand of 13 gives you 39% odds of busting. A full chart is listed below. You may notice that as your hand total gets higher, so do your odds of busting. That is because as your hand gets higher, you are getting closer to 21, so that means more cards would put you over that limit. Remember that the dealer will always draw to a 17:

Hand value — % of busting
21 – 100%
20 – 92%
19 – 85%
18 – 77%
17 – 69%
16 – 62%
15 – 58%
14 – 56%
13 – 39%
12 – 31%

In the next blog I will show the dealer’s likelihood of busting based on his up card as well as the player’s odds when that card is shown.

### Blackjack Mistakes: Going With Your Gut

Tuesday, February 16th, 2010

Nothing will get you in bigger trouble at the blackjack table than your gut. And no, I don’t mean that eating or drinking too much will make your wife hate you. I don’t mean you won’t fit in the chair or anything like that. I’m talking about playing hunches.

Hunches are important and a lot of great things have come from playing them. Listening to your gut can give you the edge in sports like baseball, in creative activities like writing or painting, or when taking a test (remember that advice of going with your first guess?). However, it doesn’t work in blackjack.

Here’s how it plays out. You’re thinking, Okay, I have 16, which is pretty high, and the dealer is showing a 7. I don’t want to bust. I think I will if I hit, so I’ll stand. I have a feeling on this one. Blackjack isn’t a game of hunches. It’s a game of odds and percentages. In poker, for instance, you can play a hunch on whether or not your cards beat your opponent’s cards, because you’re basing your decision not only on your odds, but on the behavior of the other player. With blackjack, however, you are playing against nothing but the odds. You have to make a decision about whether to hit or stand before the dealer even draws any cards. You don’t know what hole card the dealer has and you don’t know what card is next in the deck. Therefore, playing a hunch can’t help you.

What card is next in line to be dealt is next regardless of whether or not you’re feeling lucky. Blackjack basic strategy, however, has been tested time and again my statisticians and other people a lot smarter than me. Those people have found that following basic strategy gives you the best odds of winning. Following the strategy may not help you win that hand, but in the long run it will give you the best chance for success.

Looking at the above example, the player’s gut said to stand because hitting a 16 gives you a good chance of busting. That’s true. However, standing gives you an even bigger chance of being outdrawn by the dealer if he shows a 7. Blackjack basic strategy takes into account that there are more cards with a value of 10 than any other value (4 out of 13). Because of that, the strategy recognizes that you or the dealer are more likely to draw a 10 card and the dealer’s hole card is most likely to be a 10. Now let’s go back to that example.

If the dealer shows a 7 and his hole card is most likely to be a 10, then the odds say his hand is a hard 17. The dealer would stand on a hard 17, so he wouldn’t draw another card and risk busting. Since you stood on a 16, you would lose by being outdrawn. Of course, if you hit you are also most likely to draw a 10 card, which would cause you to bust, but the odds say you are more likely to draw a card of 5 or more than to outdraw a dealer who shows a 7.

In that particular example, there is no good choice. Any hand of 12-16 is a stiff hand, and the odds are against you whether you hit or stand. However, in the long run, hitting in that situation will cause you to win more often than when you stand.

Another problem with playing a hunch is that you can get caught up in streaks. If you are winning a lot then you might play more aggressive and if you’re losing you might be more cautious. However, the game of blackjack doesn’t care what kind of a streak you’re on. The cards are dealt at random, so each hand is unique. Deviating from basic strategy because you’re on a winning streak is the easiest way to put that streak to an end. Instead of letting emotions dictate your decisions, you should always play the odds, which means to stick to basic strategy.

The only exception to that rule is if you’re counting cards. If you are counting cards and feel that there is either an exceptionally large or small amount of 10 cards remaining in the deck, then you may want to deviate from basic strategy. Card counters employ a strategy that takes the odds of basic strategy and alters them by adjusting the likelihood of a 10 card being drawn.

Your gut may be good for a lot of things, such as telling whether a movie starring Adam Sandler will be any good (it won’t), whether you should wear a suit to that job interview even though the workplace is business casual (you should), and deciding whether it’s worth it to get 3 tacos from Taco Bell for only \$0.99 (it’s not). However, your gut does you no good in blackjack. Stick to the chart.